There is a difference between porros and roofs that is never mentioned, and is the reason i am sticking with porros. You get far better 3D vision with them
as the objectives are more or less twice as far apart. As magnifying flattens 3D effect you want the objectives as far apart as poss to compensate. Looking at trees and shrubs while spotting birds in them IMHO is more realistic
after all that is why we have two eyes. That said looking long distance or at flat surfaces (buildings eg) there will be no difference but that isn't birdwatching. It will be noticed up to say 100 metres. Not all porros however improve 3D, pocket or reverse porros make matters worse as the objectives are nearer than your eyes to be compact so its sort of a double whammy. I once looked through a pair of Pentax 16x24 reverse porros and there was hardly any 3D effect unless you where looking just feet away as the magnification was 16! naturally they were not very bright either.
as the objectives are more or less twice as far apart. As magnifying flattens 3D effect you want the objectives as far apart as poss to compensate. Looking at trees and shrubs while spotting birds in them IMHO is more realistic
after all that is why we have two eyes. That said looking long distance or at flat surfaces (buildings eg) there will be no difference but that isn't birdwatching. It will be noticed up to say 100 metres. Not all porros however improve 3D, pocket or reverse porros make matters worse as the objectives are nearer than your eyes to be compact so its sort of a double whammy. I once looked through a pair of Pentax 16x24 reverse porros and there was hardly any 3D effect unless you where looking just feet away as the magnification was 16! naturally they were not very bright either.